1. Field of the Invention
The present invention relates to a supporting structure of a straight down back light module and, more particularly, to a supporting structure of supporting a diffuser plate and a lamp in order to prevent them from deformation that could occur because of temperature difference and inadequate rigidity of materials.
2. Description of the Related Art
FIG. 1 shows a first conventional straight down back light module (Taiwanese Patent Publication No. 567291) including a diffuser plate, a reflector plate, a prism, a diffuser strip, two supporting pillars and a plurality of lamps. The reflector plate is located below the diffuser plate. The prism is located above the diffuser plate. The diffuser plate is located on the prism. The supporting pillars are located on the reflector plate and between the diffuser plate and the reflector plate. The lamps are also located between the diffuser plate and the reflector plate.
Referring to FIG. 1, to support the diffuser plate in the first conventional straight down back light module, several supports are often provided between the reflector plate and the diffuser plate in order to prevent deterioration in optical properties of the straight down back light module that could occur because of deformation of the diffuser plate. However, as the size of the LCD is bigger, the lamp is bigger and longer. Hence, the lamp is deformed so as to affect the optical properties of the whole straight down back light module.
FIG. 2 shows a second conventional straight down back light module (Japanese Patent No. 05-119703) for solving the problems encountered in the first conventional straight down back light module.
The second straight down back light module includes a supporting pillar provided below the lamp. However, as the size of the LCD is bigger, the diffuser plate is bigger. Hence, the diffuser plate is deformed because of heat provided by means of the lamp so as to affect the optical properties of the whole straight down back light module.